Lurasidone hydrochloride (SM-13,496) is an atypical antipsychotic marketed by Dainippon Sumitomo Pharma (DSP) and its subsidiary Sunovion Pharmaceuticals Inc. under the trade name LATUDA for the treatment of schizophrenia.
The preparation of Lurasidone (1) [JP2004224764 (SUMITOMO PHARMA, 2004)] is performed by consecutive additions of building blocks (2), (3) and (5) (Scheme 1). In a first step, 1,2-(1R,2R) bis(methanesulfonyloxymethyl)cyclohexane (2) reacts with 1-(1,2-benzisothiazol-3-yl)piperazine (3) to form the spirocyclic compound (4). Then, compound (4) reacts with bicyclo[2.2.1]heptane-2-exo-3-exo-dicarboximide (5) and forms Lurasidone (1).

3-Chloro-1,2-benzisothiazole and its synthetic precursor 1,2-benzisothiazole-3(2H)-one are used in the manufacturing process of building block (3). These intermediates are considered strong dermal, ocular, and nasal irritants which require process containment and special handling.
In addition, the processes for the preparation of Lurasidone and its intermediates use hazardous materials and involve sophisticated separation techniques which make them commercially less viable. Therefore, there exists a need to develop a process for obtaining Lurasodine in an enantiomerically pure form which is cost effective, uses available reagents, is scalable with ease and industrially feasible.